Known nonvolatile memory elements used to retrieve information by detecting variation in resistance properties include Ovonic Unified Memories (OUMs), which use chalcogenide compounds as in phase-change optical disks such as DVD-RAMs and possess the characteristic of having large resistance property variations between crystalline and amorphous states.
Meanwhile, there are recently known techniques for producing nonvolatile memory devices that use metal oxide films such as NiO, V2O5, ZnO, Nb2O5, TiO2, WO3, or CoO as data storage material layer, which take advantage of the property that their resistance drastically increases or decreases within a given voltage range. Each data storage material layer is addressed using transistors and such that are laid on each of these data storage material layers; the resistance properties of the metal oxide films are controlled by supplying a given voltage application history; and the information retained in the data storage material layers are retrieved by detecting their resistance properties (see Japanese Patent Application Kokai Publication No. (JP-A) 2004-363604 (unexamined, published Japanese patent application)).
Also known are techniques that produce memories by using the ferroelectric material of Pr0.7Ca0.3MnO3 as data storage layer, changing the resistance properties by about 10 to 1000 times by switching the voltage applied to the data storage layer made of a ferroelectric material between plus and minus at a predetermined magnitude, and detecting the resistance properties (see Applied Physics Letters, Vol. 76, No. 19 (2000), pp. 2749-2751).
On the other hand, it has been reported that the resistance property switching phenomena between 100-200Ω and 10-20Ω in nickel oxide thin films, which are formed by exposing a nickel substrate in an oxygen atmosphere, approximately match with calculation results obtained when formation and rupture of Ni fiber filaments formed in NiO matrix is assumed (see Solid-State Electronics, Vol. 7 (1964), pp. 785-797).
Similarly, it has been reported that when NiO was used as a metal oxide in a metal-metal oxide-metallic structure, a bi-stable resistance memory switching phenomenon was observed. This phenomenon could be explained by local formation and rupture of filament conduction passes, and Joule heat is considered to play an important role (see Solid-State Electronics, Vol. 7 (1964), pp. 785-797).